1. Field of the Invention
The invention is based on a calking die for calking a component in a receiving bore, in particular for calking a securing flange in a stepped receiving bore of a valve block of a traction-controlled vehicle brake system and on a calked heel for securing the flange in the bore.
2. Description of the Prior Art
From German Patent Disclosure DE 43 32 538 A1, a hydraulic unit for a traction-controlled motor vehicle brake system is known, having a valve block with a stepped receiving bore for the hydraulic part of an electromagnetically actuated valve. The hydraulic part includes a bush with a securing flange, which is axially fixed by means of a calked heel against a step of the receiving bore. To make the calked heel, a sleevelike centering die is slipped over the bush to be calked. A likewise sleevelike calking die is guided axially movably on the outer circumference of the centering die; it has a larger diameter than the receiving bore. By exerting an axially acting calking force on the calking die, a calked volume on the upper edge of the receiving bore is positively displaced as a calked bead over onto the securing flange of the bush. The resultant plastic deformation of material in the region of the calked bead secures the position of the bush in the valve block and diverts the forces, which have been transmitted to the securing flange of the bush, into the valve block; in such a case, the term “retaining calked heel” is therefore also used. So-called “sealing calked heels” are also known, which by way of example seal the hydraulic part, which is subjected to pressure fluid, of the electromagnetically actuated valve off from the environment in a fluid- and pressure-tight manner.
However, joining plays and component tolerances often lead to an eccentric position of the centering die relative to the axis of the receiving bore, so that the calking die is stamped out with a variable thickness in the circumferential direction, and if the eccentricity is great enough, peripheral portions with extremely thin calked beads can be the result. In the case of retaining calked heels, this reduces the durability, while with sealing calked heels, it impairs the sealing function.
In known sealing calked heels, additional sealing elements such as O-rings are often also used to assure an adequate sealing action, since at major calking forces the calked bead has the tendency to flow away radially inward, and consequently adequately high compressive strains cannot build up between the calked volume and the component to be calked. In assembly or in the calking operation, however, there is the risk that these sealing elements will be damaged.